1. Field of the Invention
This invention generally relates to regenerative tank-type glass melting furnaces and, more particularly, to an improved fuel burner structure suitable for use in the ports thereof.
2. Description of the Prior Art
In a conventional regenerative tank-type glass melting furnace, raw materials are continuously supplied at one end of the tank and molten glass is removed from its other end. A series of ports is located along either side of the tank adjacent the feeding end in communication with associated regenerators. The furnace is alternately fired, first from one side by drawing combustion air through the regenerators on that side and injecting gas into the preheated combustion air for directing flames across the furnace. The products of combustion are withdrawn through the opposite ports for heating the associated regenerators. Periodically, the operation is reversed and flames are directed across the furnace from the ports on the other side.
In such glass melting furnace systems, it is conventional to provide fuel burners which are recessed within and fire through openings in refractory burner blocks in the side walls of the passages connecting the regenerators with the ports (see, for example, U.S. Pat. No. 2,077,169 issued on Apr. 13, 1937). Such blocks require periodic cleaning and accordingly, it has been found desirable to use water cooled burners which can be inserted directly into the passageway and do not require burner blocks.
Of course, water cooled fuel burners suitable for use in regenerative-type glass melting furnaces are generally known in the art (see, for example, U.S. Pat. No. 1,731,248 issued on Oct. 15, 1929). As disclosed in this patent, fuel and air are admitted into the refractory combustion chamber of the furnace side ports through separate inlets, with the fuel burner extending transversely across the air passage adjacent the port opening. The fuel burner generally comprises an elongated pipe provided with a series of longitudinally spaced fuel openings. The pipe is surrounded by a hollow cylindrical shell forming a water jacket, and the shell is provided with a slot opposite the fuel openings through which the fuel is emitted for forming a wide continuous flame under low pressure. A continuous flow of water is maintained through the hollow shell to protect the burner pipe from the high temperatures occurring in the ports. An inherent disadvantage of such burners is that they cannot readily be moved to adjust the direction of firing of the flames from the port in contrast to the aforementioned style of burners.
Attempts have been made in the past to provide water cooled fuel burners adapted to fire through side openings in the ports whereby the burners can be moved around to direct the firing across the tank without the use of burner blocks. However, the devices used heretofore have not been entirely satisfactory in that the water cooled jacket of the burner included stagnant areas of low coolant flow, resulting in hot spots in the jackets which ultimately developed leaks and sprayed water on the refractory blocks of the ports, causing the refractory to spall off and be carried into the molten glass.